JP6528768B2 - Communication control device, communication control method and communication control program - Google Patents

Description

  The present invention relates to technology for controlling communication.

  In packet-switching communication generally used in Internet communication, packet loss and route change occur on the route. Therefore, in the packet switching communication, retransmission control and order control are required to deliver the transmitted data to the terminal on the receiving side in the order of transmission.

  In retransmission control, for example, when the transmission side does not receive a delivery acknowledgment (ACK; Acknowledgment) indicating that data has been delivered to the reception side, retransmission of the data is started. Alternatively, in retransmission control, for example, when the transmitting side receives a non-delivery acknowledgment (NACK; Negative Acknowledgment) indicating that data is not delivered to the receiving side, retransmission of the data is started. Alternatively, in the retransmission control, for example, when the number of data received after changing the order on the receiving side is accumulated, a retransmission of the changed data is started.

  For example, in TCP (Transmission Control Protocol), if the transmitting side does not receive ACK for a certain period of time after segment transmission, retransmission of that segment is performed. A segment is a communication unit in TCP. Furthermore, in TCP, even when it is found by the duplicate ACK that the number of segments received in an out-of-order manner is equal to or greater than the threshold value, the data in which the segments are generated is retransmitted. The specific number of the threshold varies depending on OS (Operating System) and settings.

  In order control, when data is received by the receiving side in an order different from the transmission order, the received data is aligned in the transmission order.

  For example, in TCP, when a transmitted segment arrives at the receiving end, if the segment transmitted prior to that segment has not arrived at the receiving end, the receiving end of the previously transmitted segment that has not arrived. The arrival to is awaited. Then, the segments are sorted in the order of transmission and then passed to the upper layer protocol or application.

  When data loss (ie, loss) occurs in the communication path, retransmission control and order control of retransmission waiting are performed. A large delay occurs in communication due to the retransmission control and the order control of retransmission waiting. There is a problem that such delay occurs in the packet switched communication. An example of a data communication method that avoids this order control is described in Patent Document 1.

  Patent Document 1 describes a cyclic transmission scheme that avoids order control by sequentially transmitting different data for each of a plurality of connections. As described above, in the cyclic transmission scheme described in Patent Document 1, low delay communication is realized by avoiding order control. In this method, the apparatus on the transmitting side sequentially transmits different data for each of a plurality of established connections. The device on the receiving side can use the arrived data at any time in the running application program. The device on the transmitting side described in Patent Document 1 specifies the difference between the largest number and the smallest number among the numbers assigned according to the order of transmission for each segment being transmitted via any connection. Do. If the identified difference is greater than or equal to the predetermined value, the transmitting device retransmits the earliest transmitted segment through another connection. Therefore, even if an accidental loss occurs during transmission of a segment, it is possible to avoid the order control of retransmission waiting.

  Patent Document 2 describes a relay node and a destination node connected by a working communication path and a protection communication path. When a failure occurs in the communication link of the working communication path, the relay node switches the communication path to be used to the protection communication path. Then, the relay node retransmits the data transmitted between the occurrence of the failure and the completion of the switching of the communication path.

Unexamined-Japanese-Patent No. 2010-056990 Unexamined-Japanese-Patent No. 11-308233

  For example, switching of a communication channel such as handover in a mobile network may cause a situation where all data transmitted to each communication channel is lost for a sufficiently longer period than the transmission interval of intermittently transmitted data. In that case, in transmission of data according to the cyclic transmission scheme as described in Patent Document 1, retransmission control is performed on all connections established in that period. Therefore, in the case described above, in data communication according to the cyclic transmission scheme as described in Patent Document 1, order control can not be avoided. Therefore, in the technique of Patent Document 1, when all the data transmitted by switching the communication path is lost for a period sufficiently longer than the transmission interval of the data transmitted intermittently, the communication delay can not be shortened.

  The relay node described in Patent Document 2 switches a communication channel to be used to a spare communication channel, which is the other communication channel, when a failure occurs in an active communication channel among two communication channels. Therefore, when a situation occurs in which all the data transmitted within a period sufficiently longer than the transmission interval of the data transmitted intermittently is lost, the communication link not only via the communication channel via the working channel but also via the spare channel Failure also occurs in Therefore, in that case, since a failure occurs in all communications, retransmission control is performed in the communication link via all the communication paths. As described above, in the technique of Patent Document 2, when all the data transmitted by switching the communication path is lost for a period sufficiently longer than the transmission interval of the intermittently transmitted data, the communication delay can not be shortened. .

  One of the objects of the present invention is to reduce the communication delay even if all the data transmitted by switching the communication path is lost for a period sufficiently longer than the transmission interval of the intermittently transmitted data. It is in providing a control apparatus etc.

  A communication control apparatus according to an aspect of the present invention includes a management unit that maintains a plurality of connections to a transmission destination apparatus, and a communication to the transmission destination apparatus performed by a data transmission unit through a selected connection selected from the plurality of connections. In addition to receiving the temporary disconnection notification from the determination unit which detects a temporary disconnection which is a state in which the data is suspended and transmits the temporary disconnection notification in response to detecting the temporary disconnection, the data transmission unit and The switching notification is detected within a predetermined period based on the temporary disconnection notification from the switching detection unit that detects switching of the communication path with the transmission destination device and transmits the switching notification when completion of the switching is detected. If it is received, a new selected connection is selected from the plurality of connections other than the selected connection, and the identifier of the selected connection selected is And a changing means for transmitting the serial data transmission means.

  A communication control method according to an aspect of the present invention maintains a plurality of connections to a transmission destination apparatus, and interrupts communication to the transmission destination apparatus performed by data transmission means via a selected connection selected from the plurality of connections. Data transmission means and the transmission destination in addition to receiving the temporary disconnection notice from the determination means for detecting the temporary disconnection which is in the off state and transmitting the temporary disconnection notice in response to detecting the temporary disconnection When the switching notification is received within a predetermined period based on the temporary disconnection notification from the switching detection unit that detects switching of the communication path with the device and transmits the switching notification when the completion of the switching is detected Selecting a new selected connection from the plurality of connections other than the selected connection, and transmitting the data of the selected selected connection to the data To send to the means.

A communication control program according to an aspect of the present invention includes a computer, a management unit for maintaining a plurality of connections to a transmission destination apparatus, and the transmission destination performed by a data transmission unit via a selected connection selected from the plurality of connections. In addition to receiving the temporary disconnection notification from the determination means that detects a temporary disconnection which is a state in which the communication to the device is suspended, and transmits the temporary disconnection notification in response to detecting the temporary disconnection, the data The switching detection unit detects the switching of the communication path between the transmitting unit and the transmission destination device, and transmits the switching notification when the completion of the switching is detected, and the switching detection unit transmits the switching notification within a predetermined period based on the temporary disconnection notification When a switching notification is received, a new selected connection is selected from the plurality of connections other than the selected connection, and the selected selection is made. Changing means for transmitting an identifier of Nekushon to the data transmission means, it is operated by.

  Even when all the data transmitted by switching the communication path is lost for a period sufficiently longer than the transmission interval of the data transmitted intermittently, the communication delay can be shortened.

FIG. 1 is a diagram illustrating an example of a configuration of a communication system 10 according to the first and second embodiments of the present invention. FIG. 2 is a flowchart showing an example of the operation of the second communication device 2 of the first and second embodiments to detect the occurrence of temporary disconnection. FIG. 3 is a flowchart showing an example of the operation of the communication control device 3 of the first and second embodiments when the temporary disconnection notification is received. FIG. 4 is a block diagram showing an example of a configuration of a communication system 10B of the third exemplary embodiment of the present invention. FIG. 5 is a block diagram showing an example of the operation of the second communication device 2B of the third embodiment. FIG. 6 is a flowchart showing an example of the operation of the communication control device 3B of the third embodiment. FIG. 7 is a block diagram showing an example of a configuration of a communication system 10A according to a modification of the first embodiment. FIG. 8 is a diagram showing an example of the configuration of a communication control device 3C according to the fourth embodiment of the present invention. FIG. 9 is a diagram showing an example of the configuration of a computer 1000 capable of realizing the communication control device and the communication device according to the present invention.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

First Embodiment
FIG. 1 is a diagram illustrating an example of the configuration of the communication system 10 according to the present embodiment. Referring to FIG. 1, the communication system 10 includes a first communication device 1 and a second communication device 2. The first communication device 1 and the second communication device 2 are communicably connected. The communication path connecting the first communication device 1 and the second communication device 2 is switched, for example, irregularly. For example, the first communication device 1 and the second communication device 2 are connected by wireless communication via a base station. Then, when the handover is performed by the movement of the first communication device 1 or the second communication device 2, the switching of the communication path connecting the first communication device 1 and the second communication device 2 is performed. The first communication device 1 and the second communication device 2 perform connection type communication, which is communication performed in a state where a connection which is a virtual dedicated communication path is established. As an example of connection type communication performed between the first communication device 1 and the second communication device 2, there is communication by TCP. The communication performed between the first communication device 1 and the second communication device 2 may not be communication by TCP. In the present embodiment and other embodiments of the present invention, the first communication device 1 is also described as a transmitting device. Furthermore, the second communication device 2 is also described as a transmission destination device.

  The first communication device 1 includes a data transmission unit 101 and a communication control device 3. The communication control device 3 includes a management unit 102, a change unit 103, a notification reception unit 104, and a switch detection unit 105. The management unit 102, the change unit 103, the notification reception unit 104, and the switch detection unit 105 may be components of the first communication device 1. Then, the management unit 102, the change unit 103, the notification reception unit 104, and the switch detection unit 105 may operate as the communication control device 3.

  The second communication device 2 includes a data reception unit 201, a determination unit 202, and a notification transmission unit 203.

  The data transmission unit 101 transmits data at a predetermined timing. The data transmission unit 101 may transmit data, for example, at predetermined constant intervals.

  The management unit 102 manages a plurality of connections established in the first communication device 1. The management unit 102 manages a plurality of connections, including the connection used for data transmission. The management of the connection is, for example, processing to maintain the established state so that the connection is not disconnected.

  The data reception unit 201 receives data transmitted by the data transmission unit 101 of the first communication device 1.

  When the interval between the times when the data reception unit 201 receives data exceeds the predetermined threshold, the determination unit 202 generates “temporary communication channel disconnection” in which the communication channel is temporarily disconnected. It is determined that In the description of the present embodiment and other embodiments, the communication channel temporary disconnection is also described as “temporary disconnection”.

  If the notification transmission unit 203 determines that the communication channel temporary disconnection has occurred, the “communication channel temporary disconnection notification” is a notification indicating that it is determined that the communication channel temporary disconnection has occurred. Transmit to the first communication device 1. In the description of the present embodiment and other embodiments, the communication channel temporary disconnection notification is also referred to as “temporary disconnection notification”.

  The notification receiving unit 104 receives a communication channel temporary disconnection notification from the notification transmitting unit 203 of the second communication device 2.

  The switching detection unit 105 monitors switching of the communication path. For example, the switching detection unit 105 may constantly monitor switching of the communication path. Then, the switching detection unit 105 detects the completion of switching of the communication path.

  When the notification receiving unit 104 receives the temporary disconnection notification and the switching detection unit 105 detects the completion of the switching of the communication path, the changing unit 103 is used to transmit data from a plurality of connections managed by the management unit 102. Select a connection that is not In the description of the present embodiment, the selected connection is also referred to as a selected connection. The changing unit 103 designates the selected connection as a connection to be used for data transmission. The changing unit 103 may specify the selected connection as a connection to be used for data transmission, for example, by transmitting the identifier of the selected connection to the data transmission unit 101. In that case, for example, when receiving the identifier of the connection, the data transmission unit 101 may be designed to change the connection used for data transmission to the connection specified by the received identifier. In the following description, the connection used by the data transmission unit 101 for data transmission is also referred to as a transmission connection.

  Next, operations of the first communication device 1 and the second communication device 2 of the present embodiment will be described in detail with reference to the drawings.

  FIG. 2 is a flowchart showing an example of the operation of the second communication device 2 of the present embodiment for detecting the occurrence of a temporary disconnection. At the start of the operation illustrated in FIG. 2, the data transmission unit 101 of the first communication device 1 transmits data. The method for the data transmission unit 101 to transmit data may be, for example, a transmission method based on TCP. The data transmission unit 101 transmits data, for example, at predetermined fixed time intervals.

  When data is transmitted to the data receiving unit 201 (Yes in step S101), first, the data receiving unit 201 receives the data transmitted by the data transmitting unit 101 (step S102). The data reception unit 201 may receive data as long as the data transmission unit 101 can receive data. For example, when the data transmission unit 101 transmits data based on TCP, the data reception unit 201 may receive the transmitted data based on TCP as well. The data receiving unit 201 may transmit the time at which the data was received to the determining unit 202. When the data receiving unit 201 receives data, for example, the data receiving unit 201 may transmit a notification indicating that the data has been received to the determining unit 202. In that case, the determination unit 202 may regard the time when the notification indicating that the data is received is received as the time when the data reception unit 201 receives the data. When data is not transmitted (No in step S101), the communication control device 3 performs the operation of step S103.

  The determination unit 202 determines whether the data reception interval, which is an interval of time at which the data reception unit 201 receives data, exceeds a threshold (step S103). The determination unit 202 only needs to store the time when the data reception unit 201 received data last. Then, the determination unit 202 may specify the time elapsed from the time when the data reception unit 201 received data last. If the time elapsed from the time when the data reception unit 201 last received data exceeds the threshold, the determination unit 202 may determine that the data reception interval exceeds the threshold. As described above, when it is determined that the data reception interval exceeds the threshold, the determination unit 202 determines that temporary disconnection has occurred. If the time elapsed from the time when the data reception unit 201 last received data does not exceed the threshold, the determination unit 202 may determine that the data reception interval does not exceed the threshold. If it is determined that the data reception interval does not exceed the threshold, the determination unit 202 determines that temporary disconnection has not occurred. The determination unit 202 may determine whether the data reception interval exceeds a predetermined threshold based on the stored time and the time when the data reception unit 201 newly receives data. The above-mentioned threshold may be given in advance. Alternatively, for example, the determination unit 202 may determine the above-described threshold based on an interval at which the data reception unit 201 receives data within a predetermined period.

  If the data reception interval does not exceed the predetermined threshold (No in step S103), the second communication device 2 next performs the operation of step S101. The data receiving unit 201 waits for the next data transmitted from the first communication device 1.

  If the data reception interval exceeds the predetermined threshold (Yes in step S103), the notification transmission unit 203 transmits a temporary disconnection notification to the notification reception unit 104 (step S104). Then, the second communication device 2 ends the operation shown in FIG. After the operation of step S104, the operation of the second communication device 2 may return to step S102.

  Next, the operation of the communication control device 3 when the temporary disconnection notification is received will be described.

  FIG. 3 is a flowchart showing an example of the operation of the communication control device 3 of the present embodiment when the temporary disconnection notification is received. When the notification transmitting unit 203 of the second communication device 2 transmits a temporary disconnection notification, the communication control device 3 performs the operation shown in FIG. Further, the switch detection unit 105 of the communication control device 3 monitors a communication path used in communication between the first communication device 1 and the second communication device 2. Then, when switching of the communication channel used in the communication between the first communication device 1 and the second communication device 2 occurs, the switching detection unit 105 detects the completion of the switching.

  When the notification transmitting unit 203 transmits the temporary disconnection notification, the notification receiving unit 104 receives the temporary disconnection notification (step S111). The notification receiving unit 104 may transmit the received temporary disconnection notification to the changing unit 103.

  The change unit 103 that has received the temporary disconnection notification identifies a time based on the temporary disconnection notification, and uses the identified time as a reference time. The time based on the temporary disconnection notification may be, for example, the time when the changing unit 103 receives the temporary disconnection notification. The time based on the temporary disconnection notification may be, for example, the time when the notification receiving unit 104 receives the temporary disconnection notification. The time based on the temporary disconnection notification may be the time when the temporary disconnection notification was sent. In that case, the notification transmission unit 203 may transmit the transmission time of the temporary disconnection notification to the notification receiving unit 104 in addition to the temporary disconnection notification. The time based on the temporary disconnection notification may be the time when the determination unit 202 determines that a temporary disconnection has occurred. In that case, the determination unit 202 may transmit, to the notification transmission unit 203, a data value indicating the time when it is determined that a temporary disconnection has occurred. Then, in addition to the temporary disconnection notification, the notification sending unit 203 may send to the notification receiving unit 104 a data value indicating the time when it is determined that the temporary disconnection has occurred.

  Further, the change unit 103 sets a detection period based on the reference time. Then, the changing unit 103 determines whether or not switching of the communication path has been detected within the detection period (step S112).

  The detection period is, for example, a period determined based on a reference time. The length of the detection period may be a period of a predetermined length. In that case, the changing unit 103 may set, for example, a reference time or a time before a predetermined time before the reference time as the start time of the detection period. Then, the changing unit 103 may set, for example, a reference time or a time after a predetermined time after the reference time as the end time of the detection period. The length of the detection period may not be fixed. In that case, the changing unit 103 may set, for example, a reference time or a time before a predetermined time before the reference time as the start time of the detection period. Then, the changing unit 103 may set the maximum value that can be set as the time to the end time of the detection period. The change unit 103 may not set the end time of the detection period. Since the reference time is a time based on the temporary disconnection notification, the detection period can be regarded as a period determined based on the temporary disconnection notification.

  For example, when the first communication device 1 communicates with the second communication device 2 wirelessly, switching of the communication path also occurs, for example, by switching of a wireless base station that relays communication by wireless. Generally, a device that communicates wirelessly has information that identifies a wireless base station that relays communication. For example, the switch detection unit 105 may detect the switch of the communication path by detecting a change in the wireless base station that relays the wireless communication performed by the first communication device 1. The switching detection unit 105 may detect switching of the communication path by a method according to the type of communication line to which the first communication device 1 is connected.

  If switching of the communication path is not detected within the detection period (No in step S112), the communication control device 3 next performs the operation of step S111. That is, the notification receiving unit 104 waits for a temporary disconnection notification to be transmitted next.

  If the end time is determined in the detection period corresponding to the reception of the temporary disconnection notification and switching of the communication path is not detected within the detection period, the communication control device 3 performs processing based on the temporary disconnection notification. Absent. That is, when the switching of the communication path is not detected within the detection period corresponding to the reception of the temporary disconnection notification, the communication control device 3 ignores the temporary disconnection notification.

  When switching of the communication path is detected within the detection period (Yes in step S112), the changing unit 103 is a connection that the data transmitting unit 101 uses to transmit data to the second communication device 2, a transmission connection Are changed (step S113). Then, the communication control device 3 ends the operation shown in FIG. After step S113, the operation of the communication control device 3 may return to step S111.

  As described above, when the end time of the detection period is not determined, the changing unit 103 waits for detection of switching of the communication channel by the switching detection unit 105. In that case, the changing unit 103 switches the communication path whenever the switching of the communication path is detected whenever the temporary disconnection notification is received.

  The present embodiment has an effect that the communication delay can be shortened even when all the data is lost due to the switching of the communication channel for a period sufficiently longer than the transmission interval of the intermittently transmitted data.

  The reason is that the change unit 103 changes the transmission connection after the change detection unit 105 detects completion of the switching of the communication channel when it is notified that the occurrence of the communication channel temporary disconnection has been determined. is there.

  When switching of the communication path is being performed, in the connection to which data is transmitted before the switching of the communication path is completed, since the transmitted data is lost, order control is performed. If the transmission connection is switched before the switching of the communication channel is completed, data is transmitted via the switched transmission connection, and all the transmitted data is lost. Therefore, order control is implemented also in the transmission connection after switching. When each of the plurality of connections is sequentially switched to the transmission connection before the switching of the communication path is completed, order control is performed on all of the plurality of connections. Therefore, even if the switching of the communication path is completed, the order control is performed on all of the plurality of connections, which further delays the communication.

  On the other hand, in the present embodiment, the transmission connection is changed after the completion of the switching of the communication path is detected. Therefore, when the switching of the communication path is performed, order control is performed other than the connection set as the transmission connection. Not implemented. Therefore, after the completion of the switching of the communication path is detected, order control is not performed on the changed transmission connection. Therefore, there is no communication delay that occurs because order control is implemented. Therefore, in the present embodiment, the communication delay can be shortened.

Second Embodiment
Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing the configuration of the communication system 10 of the present embodiment. The configuration of the communication system 10 of the present embodiment is the same as the configuration of the communication system 10 of the first embodiment. The following description will focus on the differences between the present embodiment and the first embodiment.

  In the present embodiment, the data transmission unit 101 transmits, in addition to the data to be transmitted, a transmission time that is the time when the data is transmitted. The data transmission unit 101 may add transmission time data, which is data representing a transmission time of the data, to transmission data, which is data to be transmitted. Then, the data transmission unit 101 may transmit the transmission data to which the transmission time data is added to the second communication device 2.

  The data reception unit 201 of the second communication device 2 transmits the transmission time data added to the received transmission data to the determination unit 202.

  The determination unit 202 stores the transmission time data added to the transmission data that the data reception unit 201 received last. When the data reception unit 201 newly receives transmission data, the determination unit 202 determines whether the data reception interval exceeds a threshold, as in the determination unit 202 of the first embodiment. If the data reception interval does not exceed the threshold, the determination unit 202 stores the transmission time data transmitted in addition to the newly received transmission data as the last received transmission data. If the data reception interval exceeds the threshold value, the determination unit 202 transmits, to the notification transmission unit 203, the transmission time data stored in the transmission data that has been added to the last received transmission data.

  The notification transmission unit 203 transmits the transmission time data stored in the determination unit 202 in addition to the temporary disconnection notification when the data reception interval exceeds the threshold. In that case, the notification transmission unit 203 may add transmission time data to the temporary disconnection notification. Then, the notification transmission unit 203 may transmit the temporary disconnection notification to which the transmission time data is added.

  The notification receiving unit 104 receives transmission time data from the notification transmitting unit 203 in addition to the temporary disconnection notification. The notification receiving unit 104 may receive the temporary disconnection notification to which the transmission time data is added as described above.

  The changing unit 103 sets the time represented by the transmission time data received by the notification receiving unit 104 as the start time of the detection period.

  The transmission time data may be a data value representing the transmission time. The transmission time data may be, for example, a sequence number or an ID (Identifier) that can specify the order of transmission assigned to each of the transmitted data. The transmission time data may be, for example, data reception time, which is the time when the data reception unit 201 receives data.

  When the transmission time data is a sequence number, for example, the changing unit 103 may hold in advance the transmission time and sequence number of the data whose transmission time is specified, and the transmission interval. In the following description, the transmission time of the data whose transmission time is specified and held by the change unit 103 will be referred to as a reference transmission time. Furthermore, the sequence number of the data whose transmission time is specified and held by the changing unit 103 is referred to as a reference sequence number. The reference sequence number may be an initial value of the sequence number. In that case, the reference transmission time may be a time at which data to which a sequence number, which is an initial value, is assigned is transmitted. The changing unit 103 may obtain, for example, the initial value of the sequence number, the transmission time of the data to which the sequence number is assigned as the initial value, and the transmission interval from the data transmission unit 101 in advance. The changing unit 103 may specify the number of times data has been transmitted after the reference time, based on the difference between the sequence number received by the notification receiving unit 104 and the reference sequence number. The changing unit 103 transmits the data to which the sequence number received by the notification receiving unit 104 is added from the reference time based on the number of times the data is updated after the reference time and the transmission interval at which the data is transmitted. The time elapsed by the time may be estimated. As described above, the changing unit 103 assigns the sequence number received by the notification receiving unit 104 based on the sequence number received by the notification receiving unit 104 as transmission time data, the reference transmission time and the reference sequence number, and the transmission interval. Estimate the time when the received data was sent.

  When the notification transmission unit 203 transmits, as transmission time data, a data value representing a reception time, which is a time when the data reception unit 201 receives data, the change unit 103 determines that the received transmission time data indicates time than The time before the delay time may be estimated as the transmission time. The delay time may be a representative value of the time required to transmit data from the first communication device 1 to the second communication device 2. The representative value may be, for example, an experimentally derived mean value, a median value, or another statistic value.

  Next, operations of the first communication device 1 and the second communication device 2 of the present embodiment will be described in detail with reference to the drawings. The following describes the case where the data transmission unit 101 transmits data to which transmission time data representing the data transmission time is added.

  FIG. 2 is a flowchart showing an example of the operation of the second communication device 2 of the present embodiment for detecting the occurrence of a temporary disconnection.

  When data is transmitted to the data receiving unit 201 (Yes in step S101), the data receiving unit 201 receives data to which transmission time data is added (step S102). When data is not transmitted to the data receiving unit 201 (No in step S101), the communication control device 3 next performs the operation of step S103.

  The operation of the determination unit 202 in step S103 is the same as the operation in step S103 of the determination unit 202 of the first embodiment. As described above, the determination unit 202 only needs to store the time when the data reception unit 201 received data last. Then, in step S103, the determination unit 202 determines whether the data reception interval exceeds the threshold value by comparing the time elapsed from the time when the data reception unit 201 received data last and the threshold value. do it. The determination unit 202 compares the time elapsed from the stored time until the time when the data reception unit 201 newly receives data with the threshold to determine whether the data reception interval exceeds the threshold. It may be determined.

  If the data reception interval does not exceed the predetermined threshold (No in step S103), the communication control device 3 next performs the operation of step S101. Then, the data receiving unit 201 continues receiving data.

  As a result of the determination by the determination unit 202, when the data reception interval exceeds the predetermined threshold (Yes in step S103), the notification transmission unit 203 transmits transmission time data in addition to the temporary disconnection notification (step S104). ).

  FIG. 3 is a flowchart showing an example of the operation of the communication control device 3 of the present embodiment when the temporary disconnection notification is received.

  First, the notification receiving unit 104 receives, for example, a temporary disconnection notification and transmission time data added to the temporary disconnection notification. (Step S111).

  When the notification receiving unit 104 receives the temporary disconnection notification and the transmission time data added to the temporary disconnection notification, the switching detection unit 105 determines a detection period. The switch detection unit 105 first specifies the time represented by the transmission time data received by the notification reception unit 104. The switching detection unit 105 sets the specified time as the start time of the detection period. The switching detection unit 105 determines the end time of the detection period according to a predetermined determination method. The switching detection unit 105 may determine the end time of the detection period, for example, by any of the methods for determining the end time of the detection period in the first embodiment.

  When the switching detection unit 105 detects switching of the communication path within the detection period (Yes in step S112), the changing unit 103 changes the transmission connection as in the changing unit 103 of the first embodiment (step S113). ). When the switching detection unit 105 detects switching of the communication path within the detection period (No in step S112), the communication control device 3 next performs, for example, the operation of step S111.

  The present embodiment has the same effect as the first embodiment. The reason is the same as the reason for the effect of the first embodiment.

  The present embodiment has the second effect that the communication delay can be further shortened.

  The reason is that the change unit 103 changes the transmission connection when the switching of the communication path is detected in the detection period in which the transmission time of the last transmitted data or the estimated time of the transmission time is the start time. It is. Therefore, even if the variation of the period in which all the transmitted data is lost is large, the period can be specified more accurately. Therefore, since the order control can be avoided more reliably, the communication delay can be shortened. In addition, since the lost data can be accurately grasped, only the lost data can be transmitted via the post-change transmission connection. Therefore, communication delay can be further shortened.

Third Embodiment
Next, a third embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 4 is a block diagram showing an example of the configuration of the communication system 10B of the present embodiment.

  Referring to FIG. 4, the communication system 10B includes a first communication device 1B and a second communication device 2B. The first communication device 1B and the second communication device 2B can communicate with each other.

  The first communication device 1B includes a data transmission unit 101 and a communication control device 3B.

  The communication control device 3B includes a management unit 102, a change unit 103, a delivery confirmation reception unit 106, a determination unit 107, and a switch reception unit 108.

  The second communication device 2B includes a data reception unit 201, a delivery confirmation transmission unit 204, a switching detection unit 205, and a switching transmission unit 206.

  The data transmission unit 101 and the data reception unit 201 operate in the same manner as the data transmission unit 101 and the data reception unit 201 of the first embodiment, respectively.

  The managing unit 102 manages a plurality of connections established between the first communication device 1B and the second communication device 2B, similarly to the managing unit 102 of the first embodiment.

  When the data reception unit 201 receives data, the delivery confirmation transmission unit 204 transmits a delivery confirmation regarding the data to the first communication device 1B. The delivery confirmation may be, for example, a predetermined data value or signal.

  The delivery confirmation receiving unit 106 receives the delivery confirmation from the delivery confirmation transmitting unit 204 of the second communication device 2B. When the delivery confirmation is received, the delivery confirmation receiving unit 106 transmits, for example, the time when the delivery confirmation is received to the determination unit 107.

  The determination unit 107 stores the time when the delivery confirmation receiving unit 106 last received the delivery confirmation. When the determination unit 107 receives the time when the delivery confirmation is newly received from the delivery confirmation receiving unit 106, the delivery confirmation receiving unit 106 receives the delivery confirmation based on the stored time and the newly received time. Derive the interval between The determination unit 107 determines whether the interval at which the delivery confirmation receiving unit 106 receives the delivery confirmation exceeds a predetermined threshold. If the interval at which the delivery confirmation receiving unit 106 receives the delivery confirmation exceeds the predetermined threshold, the determining unit 107 determines that a communication channel temporary disconnection has occurred. Then, when the interval at which the delivery confirmation receiving unit 106 receives the delivery confirmation exceeds the predetermined threshold, the determining unit 107 transmits a temporary disconnection notification to the changing unit 103.

  Similar to the switching detection unit 105 of the first embodiment, the switching detection unit 205 monitors switching of the communication path used for data transmission between the first communication device 1B and the second communication device 2B. Do. Then, the switching detection unit 205 detects the completion of switching of the communication path.

  When the switching detection unit 205 detects the completion of switching of the communication path, the switching transmission unit 206 transmits a switching notification to the first communication device 1B. The switching notification may be, for example, a predetermined data value or signal.

  The switching reception unit 108 receives the switching notification from the second communication device 2B.

  The change unit 103 receives the temporary disconnection notification from the determination unit 107. For example, the changing unit 103 sets the time when the temporary disconnection notification is received as the reference time. The change unit 103 may set the time when the determination unit 107 determines that the communication channel temporary disconnection has occurred as the reference time. In that case, the change unit 103 may receive from the determination unit 107 the time when the determination unit 107 determines that the communication channel temporary disconnection has occurred. And the change part 103 sets a detection period based on reference time similarly to the change part 103 of 1st Embodiment. When the switching reception unit 108 receives the switching notification within the set detection period, the changing unit 103 changes the transmission connection as in the case of the changing unit 103 in the first embodiment.

  Next, the operation of the second communication device 2B of the present embodiment will be described in detail with reference to the drawings.

  FIG. 5 is a block diagram showing an example of the operation of the second communication device 2B of the present embodiment. At the start of the operation shown in FIG. 5, the data transmission unit 101 of the first communication device 1B transmits data to the second communication device 2B.

  The data receiving unit 201 receives data (step S201).

  In response to the data reception unit 201 receiving data, the delivery confirmation transmission unit 204 transmits a delivery confirmation to the first communication device 1B (step S202).

  As described above, the switching detection unit 205 monitors switching of the communication path between the first communication device 1B and the second communication device 2B. Then, the switching detection unit 205 detects the completion of switching of the communication path. If switching of the communication path is not detected by the switching detection unit 205 (No in step S203), the second communication device 2B next performs, for example, the operation of step S201. Then, the data receiving unit 201 waits until the next data is sent. When switching of the communication path is detected by the switching detection unit 205 (Yes in step S203), the switching detection unit 205 transmits a switching notification to the first communication device 1B (step S204).

  Next, the operation of the communication control device 3B of the present embodiment will be described in detail with reference to the drawings.

  FIG. 6 is a flowchart showing an example of the operation of the communication control device 3B of the present embodiment. At the start of the operation shown in FIG. 6, the data transmission unit 101 transmits data to the second communication device 2B. Then, the second communication device 2B that has received the data sends a delivery confirmation of the received data back to the first communication device 1B.

  When the delivery confirmation of the data is transmitted to the delivery confirmation receiving unit 106 (Yes in step S211), the delivery confirmation receiving unit 106 receives the delivery confirmation from the second communication device 2B (step S212). The delivery confirmation receiving unit 106 transmits the time when the delivery confirmation is received to the determination unit 107. When the delivery confirmation of the data is not transmitted to the delivery confirmation receiving unit 106 (No in step S211), the communication control device 3B next performs the operation of step S213.

  As described above, the determination unit 107 stores the time when the delivery confirmation receiving unit 106 last received the delivery confirmation. The determination unit 107 may specify, for example, the time elapsed from the time when the delivery confirmation receiving unit 106 received the delivery confirmation last. Then, the determination unit 107 may compare the time elapsed from the time when the delivery confirmation receiving unit 106 received the delivery confirmation last and the predetermined threshold. If the time elapsed from the time when the delivery confirmation receiving unit 106 last received the delivery confirmation exceeds the threshold, the determination unit 107 may determine that the interval of receiving the delivery confirmation exceeds the threshold. If the time elapsed from the time when the delivery confirmation receiving unit 106 last received the delivery confirmation does not exceed the threshold, the determination unit 107 may determine that the interval of reception of the delivery confirmation does not exceed the threshold. When the determination unit 107 newly receives the delivery confirmation received from the delivery confirmation receiving unit 106, it receives the delivery confirmation that is the difference between the time when the delivery confirmation was received and the stored time when the delivery confirmation was received. Interval may be derived. The determination unit 107 may determine whether or not the interval of reception of the derived delivery confirmation exceeds a predetermined threshold.

  If the interval of reception of the delivery confirmation does not exceed the predetermined threshold (No in step S213), the communication control device 3B next performs the operation of step S211. The delivery confirmation receiving unit 106 waits until the next delivery confirmation is transmitted.

  If the interval of reception of the delivery confirmation exceeds the predetermined threshold (Yes in step S213), the determination unit 107 determines that a communication channel temporary disconnection has occurred (step S214).

  When it is determined that the communication channel temporary disconnection has occurred, the changing unit 103 sets the detection period as described above. Then, the changing unit 103 determines whether or not switching of the communication path has been detected within the detection period (step S215). For example, when the switching reception unit 108 receives the switching notification within the detection period, the changing unit 103 may determine that switching of the communication channel is detected within the detection period. For example, when the switching reception unit 108 does not receive the switching notification within the detection period, the changing unit 103 may determine that switching of the communication channel is not detected within the detection period.

  If switching of the communication path is not detected within the detection period (No in step S215), the communication control device 3B next performs, for example, the operation of step S211.

  If switching of the communication channel is detected within the detection period (Yes in step S215), the changing unit 103 changes the transmission connection as in the first embodiment (step S216).

  The present embodiment has the same effect as that of the first embodiment even when the second communication device 2B that receives data can not determine the temporary communication disconnection.

  The reason is that the delivery confirmation transmission unit 204 transmits a delivery confirmation to the first communication device 1B in response to the data reception by the data receiving unit 201. Then, based on the interval of reception of the delivery confirmation transmitted by the delivery confirmation transmission unit 204, the change unit 103 determines whether or not the communication interruption has occurred.

  The present embodiment has the same effect as that of the first embodiment even when the first communication device 1B that transmits data can not detect the completion of the switching of the communication path.

  The reason is that the switching transmission unit 206 transmits a switching notification to the first communication device 1B when the switching detection unit 205 included in the second communication device 2B that receives data detects completion of the switching of the communication path. It is from. Then, when the switching reception unit 108 receives the switching notification within the detection period, the changing unit 103 determines that the communication channel has been switched within the detection period.

<Modification>
In the first to third embodiments, the switching detection unit 205 may be included in a switching detection device not illustrated in FIGS. 1 and 4. In the first and second embodiments, the switch detection unit 205 of the switch detection device may transmit the switch notification to the first communication device 1. In that case, the communication control device 3 may further include the switching reception unit 108 as in the case of the communication control device 3B of the third embodiment. In the third embodiment, the switching detection unit 205 of the switching detection device may transmit the switching notification to the first communication device 1B.

  In the first and second embodiments, the communication control device 3 is included in the first communication device 1. However, the communication control device 3 may be included in the second communication device 2. Alternatively, some of the components of the communication control device 3 may be included in the first communication device 1. Then, components of the communication control device 3 may be included in the second communication device 2 except the components included in the first communication device 1.

  Similarly in the third embodiment, the communication control device 3B is included in the first communication device 1B. However, the communication control device 3B may be included in the second communication device 2B. Alternatively, some of the components of the communication control device 3B may be included in the first communication device 1B. Then, the components of the communication control device 3B may be included in the second communication device 2B, except the components included in the first communication device 1B.

  In the first embodiment, for example, the second communication device 2 may include the managing unit 102 and the changing unit 103 instead of the first communication device 1. In that case, the notification transmitting unit 203 and the notification receiving unit 104 are not necessary. The first communication device 1 may include the switch transmission unit 109 described later. The second communication device 2 may include the switching reception unit 207 described later. When the switching detection unit 105 detects the completion of the switching of the communication path, the switching transmission unit 109 transmits a switching notification indicating that the switching of the communication path is completed. The switching reception unit 207 receives the switching notification transmitted by the switching transmission unit 109. The change unit 103 included in the second communication device 2 newly sets the transmission connection as the transmission connection when the switch transmission unit 109 receives the switch notification within the detection period set in the same manner as the change unit 103 of the first embodiment Decide which connection to use. The second communication device 2 may further include a change instructing unit 208 that transmits an instruction to use the determined transmission connection for transmission to the first communication device 1. The data transmission unit 101 may change the transmission connection according to the instruction received from the change instruction unit 208.

  FIG. 7 is a block diagram showing an example of a configuration of a communication system 10A according to a modification of the first embodiment. In the example shown in FIG. 7, the second communication device 2A, not the first communication device 1A, includes the communication control device 3A.

  In the present variation, the first communication device 1A includes a data transmission unit 101, a switching detection unit 105, and a switching transmission unit 109. The second communication device 2A includes a data receiving unit 201 and a communication control device 3A. Communication control device 3A includes a management unit 102, a change unit 103, a determination unit 202, a switch reception unit 207, and a change instruction unit 208.

  Further, in the first and second embodiments, the notification transmission unit 203 may transmit the temporary disconnection notification a plurality of times within a predetermined transmission period instead of once. The transmission period may be a predetermined fixed period. The transmission period may be a period until the data reception unit 201 receives data after the determination unit 202 determines that the communication channel has been temporarily disconnected. The transmission period is a statistic derived from the delay time of the round trip between the first communication device 1 and the second communication device 2 measured in advance, or the delay time of the round trip measured in the past. May be The statistic is, for example, an average value, a median value, or a median value. When the notification transmitting unit 203 transmits the temporary disconnection notification a plurality of times, the notification transmitting unit 203 may include, in the temporary disconnection notification, an identifier specifying the determination of the occurrence of the communication channel temporary disconnection based on the temporary disconnection notification. .

  In the third embodiment, for example, when delivery confirmation is made in the lower layer communication protocol among the communication protocols used for communication, the delivery confirmation receiving unit 106 detects the delivery confirmation based on the lower layer communication protocol. You may Alternatively, the first communication device 1B may not include the delivery confirmation receiving unit 106. The second communication device 2 may not include the delivery confirmation transmission unit 204. Then, the first communication device 1 may include a delivery confirmation unit that detects a delivery confirmation in a lower layer communication protocol in which the delivery confirmation is performed. TCP is an example of a communication protocol for which delivery confirmation is made as described above.

<First implementation example>
Next, a first implementation example, which is an implementation example based on the first embodiment, will be described.

  In this implementation example, the first communication device 1 and the second communication device 2 are communication terminals having a central processing unit, a memory, a storage device, and a network connection function.

  The first communication device 1 is, for example, a portable communication terminal device connected via a base station to a mobile network communicably connected to the Internet. The first communication device 1 moves by the movement of the user holding the first communication device 1. The movement of the first communication device 1 switches the base station to which the first communication device 1 is connected. The switching detection unit 105 detects switching of the base station to which the first communication device 1 is connected in the mobile network as switching of the communication path.

  The second communication device 2 is, for example, a server disposed on the Internet. The second communication device 2 does not move. The second communication device 2 does not detect switching of the communication network.

  The first communication device 1 and the second communication device 2 maintain two TCP connections communicably connecting each other. Data transfer is performed directly between the first communication device 1 and the second communication device 2 using a TCP connection. In the following description of this modification, one of those two TCP connections is denoted as TCP connection A. Furthermore, another one of those two TCP connections is denoted as TCP connection B.

  The first communication device 1 keeps transmitting data to the second communication device 2 using the TCP connection A at intervals of, for example, 100 milliseconds. The first communication device 1 performs connection management processing in order to maintain the state in which the TCP connection B not used for data transmission is established. The first communication device 1 transmits a keepalive message using a TCP connection, for example, every 300 milliseconds as a connection management process. The keep alive message is not data intended to exchange data between communication devices, but data intended to maintain a state in which a connection is established.

  For example, when the data reception interval exceeds 5 seconds, the second communication device 2 is set to determine that a communication temporary disconnection has occurred, which is a state in which the communication channel is temporarily disconnected. For example, after the second communication device 2 receives the data n, which is the n-th data, the data (n + 1), which is the (n + 1) -th data, arrives at the second communication device 2 even after 5 seconds. If not, the second communication device 2 determines that a temporary communication channel disconnection has occurred. When it is determined that the communication channel temporary disconnection has occurred, the second communication device 2 transmits, for example, text data “Ichijidan” to the first communication device 1 as the temporary disconnection notification. The temporary notification is not limited to the text data described above. The temporary disconnection notification may be predetermined data.

  The first communication device 1 is set to change the transmission connection, for example, when the difference between the time when the temporary disconnection notification is received and the time when the completion of the switching of the communication path is detected is within 1 second. There is. For example, when the first communication device 1 detects the completion of switching of the communication path and receives a temporary disconnection notification 100 milliseconds after the detection, the first communication device 1 uses the TCP connection B instead of the TCP connection A as a transmission connection. Decide to do.

Second Implementation Example
Next, a second implementation example, which is an implementation example based on the third embodiment, will be described.

  In this implementation example, as in the first implementation example, the first communication device 1B and the second communication device 2B are communication terminals having a central processing unit, a memory, a storage device, and a network connection function.

  In the present implementation example, the first communication device 1B is a server disposed on the Internet. The first communication device 1B does not move. Then, the first communication device 1B can not detect switching of the communication path.

  The second communication device 2B is a portable communication terminal device connected via a base station to a mobile network communicably connected to the Internet. The base station of the mobile network to which the second communication device 2B is connected is switched in response to the movement of the second communication device 2B. The second communication device 2B detects switching of the base station of the mobile network as switching of the communication path.

  For example, two TCP connections are maintained between the first communication device 1B and the second communication device 2B. Transfer of data between the first communication device 1B and the second communication device 2B is directly performed via a TCP connection. Also in this implementation example, one of those two TCP connections is denoted as TCP connection A. Also, the other of the two TCP connections is denoted as TCP connection B.

  The first communication device 1B continues to transmit data to the second communication device 2B using the TCP connection A at predetermined intervals. In this implementation, the predetermined interval is 100 milliseconds. When the second communication device 2B receives, for example, the data 1, which is the first data, from the first communication device 1B, the second communication device 2B transmits the delivery confirmation 1 indicating that the data 1 has been delivered to the first communication device 1B. Reply to The first communication device 1B receives the returned delivery confirmation 1. Similarly, between the first communication device 1B and the second communication device 2B, data transmission and a delivery confirmation reply are performed on data 2 and subsequent data representing the second data.

  The first communication device 1B performs connection management processing in order to maintain the state in which the TCP connection B not used for data transmission is established. As a connection management process, for example, the first communication device 1B transmits a keepalive message to the second communication device 2B using the TCP connection B every 300 milliseconds.

  The first communication device 1B receives the delivery confirmation n of the data n, which is the nth data being transmitted, within a predetermined time, the data which is the (n + 1) th data that is similarly transmitted (the If the (n + 1) delivery confirmation (n + 1) does not arrive, it is determined that a communication channel temporary disconnection has occurred. The predetermined time is, for example, 5 seconds. In that case, the first communication device 1B temporarily disconnects the communication path if the delivery confirmation (n + 1) of the data (n + 1) does not arrive even if 5 seconds have passed since the receipt of the delivery confirmation n of the data n. Determine that it has occurred.

  When the second communication device 2B detects the completion of the switching of the communication path, the second communication device 2B transmits a switching notification to the first communication device 1B. The switching notification may be, for example, text data such as "Tsushinrokirikae". The switching notification may be predetermined data.

  The first communication device 1B changes the transmission connection, for example, when the difference between the time when it is determined that the communication channel temporary disconnection has occurred and the time when the switching notification is received is within a predetermined time. The predetermined time is, for example, one second. In that case, for example, if the first communication device 1B receives the switching notification 100 milliseconds after determining that the communication path temporary disconnection has occurred, the first communication device 1B changes the transmission connection. Among the two TCP connections, the first communication device 1B determines a TCP connection B that is not a transmission connection as a new transmission connection. That is, the first communication device 1B decides to use the TCP connection B to transmit data.

Fourth Embodiment
Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 8 is a diagram illustrating an example of a configuration of the communication control device 3C of the present embodiment.

  Referring to FIG. 8, the communication control device 3 </ b> C of the present embodiment includes a management unit 102 and a change unit 103. The management unit 102 maintains a plurality of connections to the transmission destination apparatus. When the change unit 103 receives a switching notification from the switching detection unit 105 within a predetermined period based on the temporary disconnection notification in addition to receiving the temporary disconnection notification from the determining unit 202, a plurality of non-selected connections are received. Select a new selected connection from the connection. Then, the change unit 103 transmits the identifier of the selected selected connection to the data transmission unit 101. Determination unit 202 detects a temporary disconnection in which communication to the destination apparatus performed by data transmission unit 101 is interrupted through the selected connection selected from the plurality of connections, and detects the temporary disconnection. Send a temporary notification. The switching detection unit 105 detects switching of the communication path between the data transmission unit 101 and the transmission destination device, and transmits switching notification when completion of the switching is detected.

  The present embodiment has the same effect as the first embodiment. The reason is the same as the reason for the effect of the first embodiment.

  The communication device according to the embodiment of the present invention can be realized by a computer and a program for controlling the computer, dedicated hardware, or a combination of the computer and the program for controlling the computer and the dedicated hardware. The communication apparatus according to the embodiment of the present invention includes a first communication apparatus 1, a first communication apparatus 1A, a first communication apparatus 1B, a second communication apparatus 2, a second communication apparatus 2A, and a second communication. The apparatus 2B, the communication control apparatus 3, the communication control apparatus 3A, the communication control apparatus 3B, and the communication control apparatus 3C.

  FIG. 9 is a diagram showing an example of the configuration of a computer 1000 capable of realizing the communication device according to the embodiment of the present invention. Referring to FIG. 9, the computer 1000 includes a processor 1001, a memory 1002, a storage device 1003, and an input / output (I / O) interface 1004. Also, the computer 1000 can access the recording medium 1005. The memory 1002 and the storage device 1003 are, for example, storage devices such as a random access memory (RAM) and a hard disk. The recording medium 1005 is, for example, a storage device such as a RAM or a hard disk, a ROM (Read Only Memory), or a portable recording medium. The storage device 1003 may be the recording medium 1005. The processor 1001 can read and write data and programs from and to the memory 1002 and the storage device 1003. The processor 1001 can access, for example, another device via the I / O interface 1004. The processor 1001 can access the recording medium 1005. The storage medium 1005 stores a program that causes the computer 1000 to operate as any of the communication devices according to the embodiment of the present invention.

  The processor 1001 loads a program stored in the recording medium 1005 that causes the computer 1000 to operate as any of the communication devices according to the embodiment of the present invention to the memory 1002. Then, the processor 1001 executes the program loaded into the memory 1002, whereby the computer 1000 operates as any of the communication devices according to the embodiment of the present invention.

  The units included in the first group below are, for example, a dedicated program which can read the functions of each unit read from the recording medium 1005 storing the program into the memory 1002 and a processor 1001 for executing the program. Can be realized by The units included in the second group described below are, for example, a dedicated program that can be implemented into the functions of each unit read from the recording medium 1005 storing the program into the memory 1002, and the processor 1001 that executes the program. Can be realized by The first group includes the data transmission unit 101, management unit 102, change unit 103, notification reception unit 104, switching detection unit 105, delivery confirmation reception unit 106, determination unit 107, switching reception unit 108, and switching transmission unit 109. It is. The second group is the data reception unit 201, the determination unit 202, the notification transmission unit 203, the delivery confirmation transmission unit 204, the switch detection unit 205, the switch transmission unit 206, the switch reception unit 207, and the change instruction unit 208.

  Alternatively, part or all of the parts included in the first group and the parts included in the second group can be realized by a dedicated circuit that implements the function of each part.

  As mentioned above, although this invention was demonstrated with reference to embodiment, this invention is not limited to the said embodiment. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

  Moreover, although a part or all of the above-mentioned embodiment may be described as the following additional notes, it is not limited to the following.

(Supplementary Note 1)
Management means for maintaining a plurality of connections to the destination device;
A temporary disconnection notification, which is a state in which communication with the transmission destination device performed by the data transmission unit is interrupted via the selected connection selected from the plurality of connections, is detected, and a temporary disconnection notification is detected according to the detection of the temporary disconnection. In addition to receiving the temporary disconnection notification from the determining means for transmitting
Within a predetermined period based on the temporary disconnection notification from the switching detection unit which detects switching of the communication path between the data transmission unit and the transmission destination device and transmits the switching notification when completion of the switching is detected. If the switch notification is received on
Changing means for selecting a new selected connection from the plurality of connections other than the selected connection, and transmitting an identifier of the selected connection to the data transmission means;
A communication control apparatus comprising:

(Supplementary Note 2)
The data transmission unit transmits the data in association with the transmission time of the data, and transmits the data.
The determination means transmits a transmission time associated with the data last transmitted before the occurrence of the temporary disconnection in association with the temporary disconnection notification.
The communication control apparatus according to claim 1, wherein the change unit sets a transmission time associated with the temporary disconnection notification as a start time of the predetermined period.

(Supplementary Note 3)
The communication control device according to claim 1 or 2, wherein the determination unit detects the temporary disconnection based on a time elapsed since the transmission destination device last received data from the data transmission unit.

(Supplementary Note 4)
The data transmission means transmits the data at predetermined intervals,
The communication control apparatus according to any one of appendices 1 to 3, wherein the determination unit determines the occurrence of the temporary disconnection when the magnitude of the deviation of the interval for receiving the data from the predetermined interval exceeds a predetermined threshold.

(Supplementary Note 5)
The start time of the predetermined period is a time that is a first predetermined time before the determined time that is the time based on the temporary disconnection notification, or the last transmission time of the data before the temporary disconnection occurs, and the predetermined period The communication control device according to any one of appendices 1 to 4, wherein an end time of the time is a time after a second predetermined time from a determined time that is a time based on the temporary disconnection notification, or a reception time of the switching notification.

(Supplementary Note 6)
A transmitting device including the data transmitting means;
The transmission destination apparatus including data receiving means for notifying the determination means of the reception of the data in response to receiving the data;
The communication control device according to any one of appendices 1 to 5;
Communication system including.

(Appendix 7)
The transmission device further includes the switching detection unit and the communication control device.
The destination apparatus further includes the determination unit.
The communication system according to appendix 6.

(Supplementary Note 8)
The destination apparatus further includes confirmation transmission means for transmitting a delivery confirmation indicating that the data reception means has received the data, and the switching detection means.
The transmitting apparatus further includes confirmation receiving means for notifying the determination means of the reception time of the delivery confirmation as the reception time of the data in response to receiving the delivery confirmation, and the determination means.
The communication system according to appendix 6.

(Appendix 9)
Maintain multiple connections to the destination device,
A temporary disconnection notification, which is a state in which communication with the transmission destination device performed by the data transmission unit is interrupted via the selected connection selected from the plurality of connections, is detected, and a temporary disconnection notification is detected according to the detection of the temporary disconnection. In addition to receiving the temporary disconnection notification from the determining means for transmitting
Within a predetermined period based on the temporary disconnection notification from the switching detection unit which detects switching of the communication path between the data transmission unit and the transmission destination device and transmits the switching notification when completion of the switching is detected. If the switch notification is received on
A communication control method comprising: selecting a new selected connection from the plurality of connections other than the selected connection; and transmitting an identifier of the selected connection selected to the data transmission means.

(Supplementary Note 10)
Transmitting the data in association with the transmission time of the data;
A transmission time associated with the data last transmitted before the occurrence of the temporary disconnection is transmitted in association with the temporary disconnection notification,
The communication control method according to appendix 9, wherein a transmission time associated with the temporary disconnection notification is set as a start time of the predetermined period.

(Supplementary Note 11)
The communication control method according to appendix 9 or 10, wherein the temporary disconnection is detected based on the time elapsed since the transmission destination apparatus last received data from the data transmission means.

(Supplementary Note 12)
Transmit the data at predetermined intervals,
The communication control method according to any one of appendices 9 to 11, wherein the occurrence of the temporary disconnection is determined when the magnitude of the deviation of the interval for receiving the data from the predetermined interval exceeds a predetermined threshold.

(Supplementary Note 13)
The start time of the predetermined period is a time that is a first predetermined time before the determined time that is the time based on the temporary disconnection notification, or the last transmission time of the data before the temporary disconnection occurs, and the predetermined period The communication control method according to any one of appendices 9 to 12, wherein an end time of is a time after a second predetermined time from a determined time that is a time based on the temporary disconnection notification, or a reception time of the switching notification.

(Supplementary Note 14)
Computer,
Management means for maintaining a plurality of connections to the destination device;
A temporary disconnection notification, which is a state in which communication with the transmission destination device performed by the data transmission unit is interrupted via the selected connection selected from the plurality of connections, is detected, and a temporary disconnection notification is detected according to the detection of the temporary disconnection. In addition to receiving the temporary disconnection notification from the determining means for transmitting
Within a predetermined period based on the temporary disconnection notification from the switching detection unit which detects switching of the communication path between the data transmission unit and the transmission destination device and transmits the switching notification when completion of the switching is detected. If the switch notification is received on
Changing means for selecting a new selected connection from the plurality of connections other than the selected connection, and transmitting an identifier of the selected connection to the data transmission means;
Communication control program to operate.

(Supplementary Note 15)
Computer,
The data transmission unit that transmits the data in association with the transmission time of the data;
The determination means for transmitting a transmission time associated with the data last transmitted before the occurrence of the temporary disconnection in association with the temporary disconnection notification;
The changing unit configured to set a transmission time associated with the temporary disconnection notification as a start time of the predetermined period;
The communication control program according to appendix 14, which is operated.

(Supplementary Note 16)
Computer,
The determination means for detecting the temporary disconnection based on the time elapsed since the transmission destination device last received data from the data transmission means;
15. The communication control program according to appendix 14 or 15, which is operated.

(Supplementary Note 17)
Computer,
Said data transmission means for transmitting said data at predetermined intervals;
The determination unit that determines the occurrence of the temporary disconnection when the magnitude of the deviation of the interval for receiving the data from the predetermined interval exceeds a predetermined threshold;
The communication control program according to any one of appendices 14 to 16 which is operated.

(Appendix 18)
The start time of the predetermined period is a time that is a first predetermined time before the determined time that is the time based on the temporary disconnection notification, or the last transmission time of the data before the temporary disconnection occurs, and the predetermined period The communication control program according to any one of Appendices 14 to 17, wherein an end time of is a time after a second predetermined time from a determined time that is a time based on the temporary disconnection notification or a reception time of the switching notification.

  This application claims priority based on Japanese Patent Application No. 2014-0081114 filed on April 10, 2014, the entire disclosure of which is incorporated herein.

  The present invention is applicable to systems that are sensitive to communication delays, such as voice and interactive services.

1 first communication device 1A first communication device 1B first communication device 2 second communication device 2A second communication device 2B second communication device 3 communication control device 3A communication control device 3B communication control device 3C communication Control device 10 communication system 10A communication system 10B communication system 101 data transmission unit 102 management unit 103 change unit 104 notification reception unit 105 switching detection unit 106 delivery confirmation reception unit 107 determination unit 108 switching reception unit 109 switching transmission unit 201 data reception unit 202 Judgment unit 203 Notification transmission unit 204 Delivery confirmation transmission unit 205 Switching detection unit 206 Switching transmission unit 207 Switching reception unit 208 Change instruction unit 1000 Computer 1001 Processor 1002 Memory 1003 Storage device 1004 I / O interface 1005 Recording medium

Claims (10)

Management means for maintaining a plurality of connections to the destination device;
Detecting a temporary disconnection communication is a suspended state to transmit the data for the destination device performs the data transmission means over the selected connection selected from the plurality of connections, to detect the temporary disconnection In addition to receiving the temporary disconnection notification from the judging means for transmitting the temporary disconnection notification according to
Within a predetermined period based on the temporary disconnection notification from the switching detection unit which detects switching of the communication path between the data transmission unit and the transmission destination device and transmits the switching notification when completion of the switching is detected. If the switch notification is received on
Changing means for selecting a new selected connection from the plurality of connections other than the selected connection, and transmitting an identifier of the selected connection to the data transmission means;
A communication control apparatus comprising: The data transmission unit transmits the data in association with the transmission time of the data, and transmits the data.
Said determination means, a transmission time associated with the data sent last before the occurrence of the one o'clock cross, to send in association with the one o'clock discontinuity notification
The communication control device according to 請 Motomeko 1. The communication control device according to claim 1 or 2, wherein the determination unit detects the temporary disconnection based on a time elapsed since the transmission destination device last received data from the data transmission unit. The data transmission means transmits the data at predetermined intervals,
The determination means, the case where the magnitude of the displacement for a given space in the space for receiving the data exceeds a predetermined threshold value, the communication control according to any one of claims 1 to 3 determines the occurrence of one o'clock sectional apparatus. The start time of the predetermined period is a reference time that is a time based on the temporary disconnection notification, a time before a first predetermined time before the reference time, or the last transmission time of the data before the occurrence of the temporary disconnection There, the end time of the predetermined period, the communication control apparatus according to any one of the second predetermined time after the time than the reference time, or claims 1 to 4 wherein a reception time of the switching notification. A transmitting device including the data transmitting means;
The transmission destination apparatus including data receiving means for notifying the determination means of the reception of the data in response to receiving the data;
A communication control device according to any one of claims 1 to 5,
Communication system including. The transmission device further includes the switching detection unit and the communication control device.
The destination apparatus further includes the determination unit.
The communication system according to claim 6. The destination apparatus further includes confirmation transmission means for transmitting a delivery confirmation indicating that the data reception means has received the data, and the switching detection means.
The transmitting apparatus further includes confirmation receiving means for notifying the determination means of the reception time of the delivery confirmation as the reception time of the data in response to receiving the delivery confirmation, and the determination means.
The communication system according to claim 6. Maintain multiple connections to the destination device,
A temporary disconnection notification, which is a state in which communication with the transmission destination device performed by the data transmission unit is interrupted via the selected connection selected from the plurality of connections, is detected, and a temporary disconnection notification is detected according to the detection of the temporary disconnection. In addition to receiving the temporary disconnection notification from the determining means for transmitting
Within a predetermined period based on the temporary disconnection notification from the switching detection unit which detects switching of the communication path between the data transmission unit and the transmission destination device and transmits the switching notification when completion of the switching is detected. If the switch notification is received on
A communication control method comprising: selecting a new selected connection from the plurality of connections other than the selected connection; and transmitting an identifier of the selected connection selected to the data transmission means. On the computer,
Management processing for maintaining a plurality of connections to the destination device;
A temporary disconnection notification, which is a state in which communication with the transmission destination device performed by the data transmission unit is interrupted via the selected connection selected from the plurality of connections, is detected, and a temporary disconnection notification is detected according to the detection of the temporary disconnection. In addition to receiving the temporary disconnection notification from the determining means for transmitting
Within a predetermined period based on the temporary disconnection notification from the switching detection unit which detects switching of the communication path between the data transmission unit and the transmission destination device and transmits the switching notification when completion of the switching is detected. If the switch notification is received on
A change process of selecting a new selected connection from the plurality of connections other than the selected connection, and transmitting an identifier of the selected connection to the data transmission means;
Communication control program to execute .

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